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CHEMICAL ENGINEERING R E V I E W S
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OPERATIONS REVIEW
I Drying
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IN past years! the drying literature consisted predominantly of descriptive articles that emphasized the dryer type and/or drying conditions required to satisfy product quality considerations for specific materials. .4 feiv articles reported the results of fundamental studies, -4minimum of information \vas published on the performance characteristics of small-scale or plant-size dryers from which scale-up relationships could be developed, Drying is still an art and little work was done during the past year to bring it to the level of development of many of the other unit operations.
Drying Fundamentals
General and Review Articles. Chapters on drying were included in textbooks on the unit operations of chemical engineering by Coulson and Richardson ( 7 7A) and Badger and Banchero ( 3 A ) . Each comprises a discussion of drying fundamentals and a description of the more common types of
dryers. .I similar chapter was contained in .4gricultui a1 Process Enxinetring (22'4). Each of these would serve as an adequate introduction to the field of drying. Two brief chapters on drj,ing and dryers were included in a text edited by hIolloy i l1.i). The second edition of von Loesecke's "Drying and Dehydration of Foods" (6'.l.4), which appeared during 1953, presents a Lvealth of information on the numerous techniques used in the food industry. The various types of dryers are discussed briefly. T h e subject of dryer design is limited to the design of tunnel dryers. A complete coverage of tunnel dryers was included in .4dvuncrs in Food Research (28-i). The major topics covered Fvere : classification, mechanical construction, auxiliaries, typical commercial units, and theory of tunnel dehydration. Lapple (.329.
